The Center for Clinical Epidemiology and Biostatistics (CCEB) and the Department of Obstetrics and Gynecology of the University of Pennsylvania (Penn) propose to continue an innovative and successful research training program for clinicians in Reproductive Epidemiology, specifically designed to strengthen the links between obstetrics and gynecology and traditional epidemiology. The objective of the program is to train individuals who already are physicians to be rigorous and independent academic investigators able to use the range of approaches available in epidemiology to address issues in obstetrics and gynecology related to etiology, prognosis, prevention and early detection, treatment, clinical economics, technology assessment, medical decision making, and quality of patient care. The two- to three-year training program consists of: 1) a core curriculum of required courses in clinical epidemiology, research methodology, and biostatistics;2) a required course in reproductive epidemiology;3) elective courses;4) extensive independent readings;5) attendance at and participation in research seminars in the CCEB and the Department of Obstetrics and Gynecology;and 6) the completion of an independent research project in Reproductive Epidemiology. The specific aims of the training program are to: 1) provide in-depth knowledge of the research techniques appropriate to clinical research;2) provide opportunities for the study of topics related to obstetrics and gynecology;3) provide research experience with mentors in clinical epidemiology and obstetrics and gynecology research;and 4) bring together faculty and fellows through participation in seminar series in the CCEB and the Department of Obstetrics and Gynecology. Trainees will matriculate in the Master of Science in Clinical Epidemiology (MSCE) degree program. Strengths of the proposed program are: 1) the long history of successful research training programs in the CCEB and the Department of Obstetrics and Gynecology;2) the comprehensive course offerings and research programs that are available to trainees, 3) a history of collaborative links already forged between the CCEB and the Department of Obstetrics and Gynecology;4) and the extensive successful training records of the program directors and faculty. In addition, the availability of resources such as excellent basic laboratories in the Department of Obstetrics and Gynecology, the broad range of rich expertise of the faculties in the CCEB and the Department of Obstetrics and Gynecology, numerous existing large databases available to these groups that can be used for research projects and training, a broad array of specialized analytic capabilities available for clinical studies (e.g., clinical trials, case-control, cohort research, etc.), and the faculties'commitment to collaborative research and training, combine to provide an ideal environment for this proposed training program.